An internet worm is self-spreading malware that copies itself across networks without you clicking or installing anything. Unlike a classic virus that needs an infected file to run, a worm exploits bugs and weak settings to move automatically from one device to the next.
Scans the internet or local network for known vulnerabilities
Uses default passwords or misconfigurations to slip in
Drops a loader, then propagates to new targets from the infected host
Can add payloads like ransomware or cryptominers once inside
Sudden network slowdowns or bandwidth spikes
Services crashing or machines rebooting unexpectedly
New firewall rules or admin accounts you did not create
Security alerts about blocked exploit attempts across many hosts
Isolate affected systems from the network.
Patch the exploited vulnerability on all hosts before reconnecting.
Run a full anti-malware scan and remove persistence tasks or services.
Rotate admin passwords and keys from a clean machine.
Review logs to confirm containment and find patient zero.
Patch fast on internet-facing apps, VPNs, and OS services
Disable or restrict unused ports and services
Enforce strong, unique passwords and MFA for admin access
Segment networks and apply egress filtering to limit spread
Use EDR and IDS/IPS to spot scanning and exploitation early
Keep backups offline and test restores